# Glossary

`.desktop` file
`.directory` file
`.omf` file
application registry

The application registry is a collection of desktop entry files which register applications. The location of the application registry for the GNOME Desktop is `$XDG_DATA_DIRS:$XDG_DATA_HOME/applications/`.

desktop entry file

A data file that provides information about an item in a menu. The desktop entry file specifies the details for the item such as a name, a command to run, an icon, and so on. Desktop entry files have a `.desktop` file extension.

directory entry file

A data file that provides information about a menu. The directory entry file specifies details such as a name for the menu, a tooltip for the menu, and an icon to represent the menu. Directory entry files have a `.directory` file extension.

GConf configuration source

A storage location in the GConf repository. For example, `xml:readonly:/etc/gconf/gconf.xml.defaults`.

GConf preference key

An element in the GConf repository that corresponds to an application preference. For example, the `/apps/gnome-session/options/show_splash_screen` key corresponds to the Show splash screen on login option in the Sessions preference tool.

GConf path file

A file that lists the GConf configuration sources, and the order in which to search the sources.

GConf schema

A collective term for a schema key and a schema object.

GConf schema definition file

A GConf schema definition file lists the keys in a particular application, and defines the characteristics of the keys. GConf schemas are generated from schema definition files. Schema definition files have a `.schemas` file extension.

GConf schema key

A key that stores a schema object for a preference key. For example, `/schemas/desktop/gnome/interface/font_name` is a schema key for the `/desktop/gnome/interface/font_name` preference key.

GConf schema object

An element in a configuration source that contains information about a preference key. The schema object contains information such as a default value for the preference key, and documentation on the preference key.

glob pattern

A glob pattern is used to match a file name by using special characters such as `*` and `?`. The MIME system uses glob patterns to assign MIME types based upon filenames and often, file extensions.

Interoperable Object Reference

An Interoperable Object Reference (IOR) is a string reference to a CORBA object. An IOR encodes a hostname and port to which messages can be sent to control the object. The IOR also contains an object key to identify the object.

magic rule

A magic rule defines a file's MIME type by specifying text or binary data to search for at the beginning of the file. Offsets to look for this data are defined in a magic rule.

Menu definition files

Menu definition files define the hierarchy of menus that are used in the GNOME menu bar.

MIME

Multipurpose Internet Mail Extension.

MIME source XML file

A MIME source XML file defines how MIME types are resolved for different kinds of files. There are three ways in which this can be done: using file extensions (glob patterns), using magic rules and using XML namespaces. MIME source XML files are located in the `$XDG_DATA_DIRS:$XDG_DATA_HOME/mime/packages` directory.

MIME type

A MIME type identifies the format of a file. The MIME type enables applications to read the file. For example, an email application can use the `image/png` MIME type to detect that a Portable Networks Graphic (PNG) file is attached to an email.

MIME type database

The MIME type database is a collection of files which register MIME types for the desktop environment. The location of the MIME type database is the directory `$XDG_DATA_DIRS:$XDG_DATA_HOME/mime`.

OMF file

Open Source Metadata Framework file. This is a file that is associated with the XML file for a manual. The OMF file contains information about the manual that is used by the Help browser. OMF files have a `.omf` file extension.

PAM

Pluggable Authentication Modules.

screensaver

A screensaver is an application that replaces the image on a screen when the screen is not in use. The screensaver application for the GNOME Desktop is XScreenSaver.

screensaver display

A screensaver display is an application that displays images on the screen of the user when the screen is not in use.

UDP

User Datagram Protocol.

Uniform Resource Identifier

A Uniform Resource Identifier (URI) is a string that identifies a particular location in a file system or on the web. For example, the address of a web page is a URI.

websafe color palette

The websafe color palette is a general-purpose palette of 216 colors. The websafe color palette is designed to optimize the use of color on systems that support 8-bit color. The websafe color palette is also called the Netscape color palette and the Netscape color cube.